Terminal-ended spring blade contact arm securing means

ABSTRACT

In a switch, a case having at least one external wall with integral wall means extending therefrom inwardly into the case, at least one spring blade contact arm in the case having a free contact end and a terminal end with a tubular terminal portion which extends laterally across the end of the blade, the wall means and the terminal end of the spring blade contact arm defining a pocket closed at the bottom by the external wall, and a dielectric material substantially filling the pocket and acting to prevent separation of the contact arm and case.

United States Patent Claude V. Koch Two Rivers;

Qonald G S torms, Manitowoc, both of Wis. $8,609

July 27, 1970 Sept. 28, 197 l AMF Incorporated lnventors Appl. No. Filed Patented Assignee TERMINAL-ENDED SPRING BLADE CONTACT ARM SECURING MEANS 9 Claims, 7 Drawing Figs.

US. Cl ..200/ 166 CT, 339/218 R int. Cl 01h 1/58 Field of Search 200/166 CT, 166.1, 166 Bl-l; 339/275 T, 218 R, 218 M [56] References Cited UNITED STATES PATENTS 2,853,578 9/ 1958 Rommel et al 200/ l 66 J 3,377,450 4/1968 Grady, Jr. et al. 200/166 J 3,501,608 3/1970 Rulseh et al. 200/ l 66 Primary Examiner-H. 0. Jones Assistant ExaminerRobert A. Vanderhye Attorneys-George W. Price and Charles J. Worth Y 1 50 -;-j,/ 20 /9 54 /5 l8 4/ t 23 42 PATENTEU SEPZS .97;

SHEET 2 0F 2 FIG.2

35 FIG. 3A

INVENTOR CLAUDE V. KOCH BgOIVALD 6. 5T RMS AGENT TERMINAL-ENDED SPRING BLADE CONTACT ARM SECURING MEANS BACKGROUND AND SUMMARY OF THE INVENTION This invention relates generally to switch assemblies and more particularly to mounting spring contact arms within the switch case.

A spring contact arm or blade for a switch, commonly made of an electrically conductive leaf spring material, is usually mounted at one end on a supporting structure with its other end free to move and is provided with one or more contact faces. The blade or arm is normally provided at its fixed or supported end with terminal means for connection to an electrical conductor.

To connect such an am or blade, a fastener may be provided which extends through the plane of the blade and the supponing surface as is shown in FIG. of U.S. Pat. No. 3,391,258 granted July 2, 1968 to P. R. Vimoche, Jr. Altematively, a bracket may be provided as shown in FIGS. 2A, 2B and 2C ofU.S. Pat. No. 3,452,165 granted June 24, 1969 to R. D. Rulseh. Here again, the flat of the blade abuts the support surface which is now provided by the bracket. When the terminal means includes a threaded fastener, a threaded opening through the blade is quite common. Where mounting brackets are provided the threaded opening normally is provided in one of the bracket legs as shown in the aforenoted Rulseh patent. In both instances, the threaded extent of the opening is limited to substantially the thickness of the material.

An improved form of mounting a spring contact blade is disclosed in U.S. Pat. No. 3,501,608 granted Mar. 17, 1970 to Rulseh and Koch, which is assigned to the assignee of the present application. In this instance, the switch case is provided with a peripheral wall or flange, a portion of which defines a pocket. The contact arms, disposed in slots through this wall portion, therefore extend through the pocket which is then filled with a dielectric filler material such as an epoxy resin. When the epoxy resin sets, the blades are locked in place. While the Rulseh and Koch concept provides an approach, there are many limitations which will now be eliminated by the invention of the present application. The blades of each of the spring contact arms discussed herein and the method of making them is the subject matter of our copending application, Ser. No. 58,610 filed July 27, 1970.

An object of the present invention is to provide an improved means for mounting spring contact arms in switches which will facilitate switch assembly and provide relatively uncomplicated and rugged construction.

Another object of the present invention is to provide the foregoing with the spring contact arms having improved threaded terminal means.

And another object of the present invention is to provide the foregoing in which a wire conductor can be connected to a terminal means within or without the switch case.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawings wherein several embodiments of the invention are illustrated by way of example. It is to be expressly understood, however, that the drawings are for illustration purposes only and are not to be construed as defining the limits of the invention.

FIG. 1 is a plan view of a portion of a switch embodying one form of the invention with three spring contact blades,

FIG. 2 is an enlarged fragmentary sectional view taken on line 2-2 of FIG. 1,

FIG. 3 is an enlarged fragmentary sectional view taken on line 3-3 of FIG. 1,

FIG. 3A is a view of a modification of the construction illustrated by FIG. 3,

FIG. 4 is a plan view of a portion of a switch with a single spring contact arm and a pair of fixed contact terminals, and

LII

FIGS. 5 and 6 are fragmentary plan views illustrating two forms of the invention each for mounting a pair of spring contact arms in a switch.

DESCRIPTION OF THE INVENTION Referring now to the drawings and particularly to FIG. 1, a portion of a hollow switch case member 10, shown diagrammatically, houses three spring contact arms 30, 40 and 50 mounted therein in accordance with the present invention.

The case member 10 is provided with a main or outer wall 11 and a peripheral wall or flange of which three lengths or runs 12, 13 and 14 are, at least in part, shown. A short wall or flange 15 extends inwardly from and normal to the peripheral flange portion 12 while the opposite peripheral flange portion 14 has an enlargement to provide an inwardly disposed boss 16 in spaced axial alignment with the flange 15. The boss 16 is provided with a central through opening 17, as will be further discussed. It should be understood that the peripheral flange portions 12 and 14 are considered as external walls only to facilitate description of the invention and, alternatively, could be relatively short internal flanges enclosed within the outer walls of the case 10.

The case wall 11 is provided with a pair of integral inner L- shaped wall portions 18 and 21 which extend inwardly and are spaced between the flange 15 and boss 16, having axially ex tending legs or portions 19 and 22 respectively, which converge toward the boss 16 and legs or portions 20 and 23, respectively, extending transversely from the ends, closer to the flange 15, of the respective axial legs toward the other of the L-shaped walls. The case wall 11 also is provided with another pair of L-shaped wall portions 24 and 27, disposed transversely outwardly of the L-shaped wall portions 18 and 21, having respective axially extending legs 25 and 28, and opposed transverse legs 26 and 29, respectively.

The spring contact arm 30 is made of a blade 31 of electrically conductive spring material with a free end 32 which bears on or abuts one side of the boss 16. The blade 31, which is provided with a contact face 33 adjacent its free end 32, extends past and is engaged by the free edge of the wall portion 29. The other end of the blade 31 bears against the wall portion 22 and is formed to provide a tubular terminal portion 34, preferably with internal threads 35, disposed between the axial wall portions 22 and 28 and spaced from the transverse wall portion 29.

Referring also to FIGS. 2 and 3, the wall 11 is provided with an opening 37 which is suitably located to receive and form a socket for the terminal portion 34 which is relatively wider than the rest of the blade 31. The blade 31 is spaced from the wall by a step or shoulder portion 36 adjacent the terminal portion 34.

When the spring contact arm 30 is assembled in the case member 10 it is properly located by inserting the terminal portion 34 into its socket 37, and is correctly positioned by the engagement of the wall portions 22 and 29 so the free end 32 of the blade 31 is spring biased against the boss 16. The L- shaped wall 27 and the terminal portion 34 with the adjacent portion of the blade 31 cooperate to form or define a pocket or cavity 38 which is closed at the bottom by the exterior or case wall 11. A suitable dielectric material such as a fluid or semifluid hardenable material which sets in situ, such as an epoxy resin, is provided to fill the pocket or cavity 38 and lock the spring contact arm 30 in place.

As shown in FIG. 2, the spring contact arm 30 may be connected to an electrical conductor C by a fastener F threaded into the inner end of the terminal portion 34. Alternatively, the arm 30 may be connected to a conductor CC outside of the switch case by a fastener FF threaded into the opposite end of the terminal portion 34 disposed in the opening or socket 37 of the wall 11.

When only an internal electrical connection to the spring contact arm 30 is required, it would be preferable to omit the opening 37 from the wall 11 to remove a possible entry for foreign matter into the switch. For such instances, as shown in FIG. 3A, the wall 11 is provided with a recess 37A in place of the opening 37 and the terminal portion 34 of the blade 31 is of a suitable width to seat in the socket recess when the spring contact arm 30 is properly positioned.

The spring contact arm 40 is similar to or a mirror image of the spring contact arm 30. The arm 40 is made of an electrically conductive blade 41 with a free end 42 biased against the other side of the boss 16, a contact face 43 in spaced face to face alignment with the contact face 33, and a terminal portion 44 with internal threads 45.

The spring contact arm 40, like arm 30, is properly located by insertion of the terminal portion 44 into a socket opening or recess in wall 11 (not shown) and is correctly positioned by the L-shaped walls 18 and 24 while a step or shoulder portion (not shown) corresponding to the step or shoulder portion 36 is provided as a spacer means. The L-shaped wall 24 and the terminal portion 44 with the adjacent part of the blade 41 forms or defines a pocket or cavity 46 which corresponds to the pocket or cavity 38 and receives a suitable filler material to lock the arm 40 in its assembled position.

The spring contact arm 50 is also made of an electrically conductive blade 51 which extends axially through the opening 17 of the boss 16 to provide an exposed operable or movable end portion 52. A pair of contact faces 53 and 54 are provided each on the opposite side of the blade 51 and aligned to contact the respective contact faces 33 and 43 by movement of the free blade end 52. The blade 51, which is L-shaped, extends between the ends of the transverse wall portions 20 and 23 to the flange which cooperate to position the free end 52 to maintain the contacts 53 and 54 normally spaced from contacts 33 and 34 respectively. Of course the blade supporting portions 15, and 23 can be reproportioned or the blade 51 could be sufficiently deformed to normally hold contacts 33 and 53 or 43 and 54 in engagement.

The offset portion 57 of the L-shaped blade 51 extends away from the flange or wall portion 15 and the free end thereof is formed to provide tubular terminal portion 55 with internal threads 56 at the other end of the arm 50 which corresponds to the terminal portions 34 and 44 of arms and 40, respectively. Although not shown, the wall 11 is provided with a socket for the terminal portion 55 corresponding to the socket 37 or 37A, as required, and the leg or offset blade portion 57 provides a step or spacer means corresponding to the step or shoulder 36.

The terminal portion 55 and the offset blade portion 57 cooperate with the L-shaped wall, formed by the flange 15 and that part of the flange 12 which extends between the terminal 55 and flange 15, to form or define a pocket or cavity 58 which corresponds to the pocket or cavity 38 or 46 and is filled with a suitable material to lock the arm 50 in its assembled position.

It should be noted that each of the blades 31 and 41 can flex in only one direction, away from the boss 16. To prevent such flexure from having a deleterious effect, it is isolated from the connection at the terminal ends of the spring contact arms 30 and 40 by the wall portions 29 and 26, respectively. The blade 51 can flex to either side of its normal plane and the wall portions 20 and 23 prevent this flexure from effecting the formed connection at the terminal end of the spring contact arm 50.

Referring now to P16. 4, a modified form of switch embodying the present invention is shown. in this instance a pair of terminal contacts 60 and 61, in place of the spring contact arms 30 and 40, are fixedly mounted in slots through the flange portion 14, each on the opposite side of the boss 16 from the other.

The present invention also can be embodied in a switch with two spring contact arms as is shown in FIGS. 5 and 6. Referring particularly to FIG. 5, the spring contact arm 50 is eliminated, and spring contact arms 30 and 40 cooperate to provide a make/break switch. Accordingly, the L-shaped walls 18 and 21 are positioned closer together for proper spacing of the arms 30 and 40. The relative position of wall 24 to wall 18 and wall 27 to wall 21 is substantially the same as in FlG. 1.

The tubular terminal portions 34, 44 and 55 of spring contact arms 30, 40 and 50, respectively, are each formed or disposed on one side of the normal plane of the respective blades 31, 41 and 51. Except for the terminal portions, blades 31 and 41 are substantially uniplanar or undeformed. The blade 51, however, is L-shaped with the leg or displaced blade portion 57 being bent out of the normal blade plane in a direction opposite from the terminal portion 55.

In place of the four L-shaped wall portions 18. 21, 24 and 27, a single wall formation may be used to mount a pair of spring contact arms within a switch in accordance with the present invention. As shown in FIG. 6, an elongated C-shaped wall 65, preferably with arcuate ends or bight portions 66 and 67, is provided with a central divider portion 68 which extends axially toward the gap or breach 69 in the C-formation to divide the area within the wall 65 into two pockets or cavities 70 and 71 A pair of L-shaped spring contact arm blades 72 and 75, which correspond to blades 31 and 41, respectively, are provided. Blade 72 extends through the breach 69 into the pocket 70 along one side of the divider 68 while the blade 75 extends through the breach 69 into the pocket 71 along the other side of the divider 68. The legs or displaced portions 74 and 77 of the respective blades 72 and 75 extend along the side of the C shaped wall 65, opposite from the breach 69, in opposite directions and terminate in tubular threaded portions 73 and 76 which correspond to the respective terminal portions 34 and 44. The terminal portions 73 and 76 are each formed on one side of the normal planes of blades 72 and 75, respectively. Unlike the arm 50, the displaced portion 74 of the blade 72 is bent out of the normal blade plane in the same direction as the terminal portion 73. Blade portion 77 is similarly displaced.

It should be understood that each of the blades 72 and 75 is provided with a step or shoulder portion corresponding to the step or shoulder portion 36. Also, each of the terminal portions 73 and 76 preferably is provided with a socket cor responding to the socket 37 or 37A, as required.

As previously described with respect to others of the spring contact arms, when the blades 72 and 75 are in their respective assembled positions, the pockets or cavities 70 and 71 receive a suitable material to lock the blades in place. It should be noted that the blades 72 and 75 complete the enclosure or wall structure encircling the pockets or cavities 70 and 7 l Although several embodiments of the invention have been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes may also be made in the design and arrangement of the parts without departing from the spirit and scope of the invention as the same will now be understood by those skilled in the art.

We claim:

1. In a switch means, the combination comprising a case having at least one external wall with integral wall means extending therefrom into said case,

at least one electrically conductive spring blade contact arm disposed in said case said spring blade having a contact end free to be flexed out of the normal plane of said blade and a terminal end which is rolled to provide a tubular terminal portion disposed laterally across said terminal end,

said terminal end and said integral wall means defining a cavity closed at its bottom by said external wall, and

a dielectric material substantially filling said cavity and acting to prevent separation of said case and said contact arm supported thereby.

2. ln a switch means, the combination in accordance with claim 1 wherein said blade has an elongated flexible portion including said free end, a shoulder portion on one side of said blade adjacent to said tubular terminal portion which extends past said shoulder portion,

said shoulder portion engaging said external wall and spac ing said flexible portion therefrom, and

said external wall having socket means for the end of said tubular terminal portion which extends past said terminal portion. 3. In a switch means, the combination in accordance with claim 2 and said socket means being a recess in said external wall closing the end of said tubular terminal portion disposed therein. 4. In a switch means, the combination in accordance with claim 2 and said socket means being an opening through said external wall exposing for connection to an electrical conductor the end of said terminal portion disposed therein. 5. In a switch means, the combination in accordance with claim 2 and said integral wall means being substantially L-shaped thereby providing two sides of said cavity, and said tubular terminal portion being disposed on one side of the normal plane of the blade and with the blade adjacent thereto forming two additional sides of said cavity. 6. In a switch means, the combination in accordance with claim 5 and said integral wall means further including a wall portion engaging said blade adjacent said tubular terminal portion and on the side thereof opposite from said cavity. 7. In a switch means, the combination in accordance with claim 5 and said blade being bent in a direction away from said tubular terminal portion to form a leg portion adjacent thereto providing one of said two additional sides of said cavity.

8. in a switch means, the combination in accordance with claim 7 and said integral wall means further including wall portions spaced from said cavity toward said free contact end and engaging both surfaces of said blade 9. In a switch means, the combination in accordance with claim 2 and said integral wall means being of an elongated Cshape with a central gap in one of its elongated sides and a central wall portion extending from the other of its elongated sides toward said central gap,

another spring blade contact arm having a terminal end which is rolled to provide a tubular terminal portion disposed laterally across said terminal end,

said tubular terminal portion of each of said blades being disposed on one side of the normal plane thereof and the terminal end being bent in the same direction as said tubular terminal portion to provide a leg portion, and

said spring blade contact arms extending along said central wall portion, each on the opposite side from the other, and through said gap with said leg portions disposed adjacent said other of its elongated sides. 

1. In a switch means, the combination comprising a case having at least one external wall with integral wall means extending therefrom into said case, at least one electrically conductive spring blade contact arm disposed in said case said spring blade having a contact end free to be flexed out of the normal plane of said blade and a terminal end which is rolled to provide a tubular terminal portion disposed laterally across said terminal end, said terminal end and said integral wall means defining a cavity closed at its bottom by said external wall, and a dielectric material substantially filling said cavity and acting to prevent separation of said case and said contact arm supported thereby.
 2. In a switch means, the combination in accordance with claim 1 wherein said blade has an elongated flexible portion including said free end, a shoulder portion on one side of said blade adjacent to said tubular terminal portion which extends past said shoulder portion, said shoulder portion engaging said external wall and spacing said flexible portion therefrom, and said external wall having socket means for the end of said tubular terminal portion which extends past said terminal portion.
 3. In a switch means, the combination in accordance with claim 2 and said socket means being a recess in said external wall closing the end of said tubular terminal portion disposed therein.
 4. In a switch means, the combination in accordance with claim 2 and said socket means being an opening through said external wall exposing for connection to an electrical conductor the end of said terminal portion disposed therein.
 5. In a switch means, the combination in accordance with claim 2 and said integral wall means being substantially L-shaped thereby providing two sides of said cavity, and said tubular terminal portion being disposed on one side of the normal plane of the blade and with the blade adjacent thereto forming two additional sides of said cavity.
 6. In a switch means, the combination in accordance with claim 5 and said integral wall means further including a wall portion engaging said blade adjacent said tubular terminal portion and on the side thereof opposite from said cavity.
 7. In a switch means, the combination in accordance with claim 5 and said blade being bent in a direction away from said tubular terminal portion to form a leg portion adjacent thereto providing one of said two additional sides of said cavity.
 8. In a switch means, the combination in accordance with claim 7 and said integral wall means further including wall portions spaced from said cavity toward said free contact end and engaging both surfaces of said blade.
 9. In a switch means, the combination in accordance with claim 2 and said integral wall means being of an elongated C-shape with a central gap in one of its elongated sides and a central wall portion extending from the other of its elongated sides toward said central gap, another spring blade contact arm having a terminal end which is rolled to provide a tubular terminal portion disposed laterally across said terminal end, said tubular terminal portion of each of said blades being disposed on one side of the normal plane thereof and the terminal end being bent in the same direction as said tubular terminal portion to provide a leg portion, and said spring blade contact arms extending along said central wall portion, each on the opposite side from the other, and thrOugh said gap with said leg portions disposed adjacent said other of its elongated sides. 